Glaucus said it has an unredacted testimony from the attorney, David Mursten, that shows CEO Nick Caporella admitted to cooking the books.

"Yet in a recently un-redacted complaint, Mursten alleged that Caporella admitted to him that FIZZ" — National Beverage's Nasdaq ticker symbol — "always hit earnings targets because if the Company was short, Caporella would reach into his 'little jewel box' to manipulate earnings," the Glaucus report says.

"Mursten also alleged that Caporella admitted to him that Caporella's son and FIZZ President (Joseph) once fabricated invoices to distributors in order to fraudulently inflate the Company's reported financial performance."

Glaucus also made a number of other claims, including:

Low operating costs and increasing revenues show financial-reporting manipulation. "How does a small, regional beverage manufacturer which sells discounted brands report such low operating expenses relative to its peers?" the report says. "In our opinion, the answer is simple: Either FIZZ has revolutionized the beverage business or it is falsifying its reported financial performance"

Off-book stock gifts to employees. "Depositions under oath also indicate that Caporella gave a 'gift' of 150,000 shares of FIZZ's stock to an employee of CMA" — Corporate Management Advisors — "in 2011," the report says. "Yet FIZZ's public filings never reflect such a change in shareholding, indicating that the compensation was kept off the Company's books and records."

The use of "suspicious" third-party entities. "Other key FIZZ and CMA executives are also executives listed in the filings of separate entities controlled by Caporella that are not listed as FIZZ subsidiaries in its 10-K," the report says. "Some share the same address as the Company. Two additional recent lawsuits allege that the Company transacts with undisclosed related parties."

In a press release following the report, National Beverage said that the report is false and warned investors about selling shares due to the report.

"Shareholders are cautioned against reacting to the false statements being made," said the release. "Our financial statements have been and are routinely audited; and we reiterate that we stand behind the integrity of our financial statements and SEC filings."

Following the release of the report, shares of National Beverage fell more than 8%, to $42.67.